What does the pylon driveshaft transfer between the PRGB and the TAGB?

The pylon driveshaft serves a crucial function in the relationship between the Power Reduction Gearbox (PRGB) and the Transmission Accessory Gearbox (TAGB). It is specifically designed to transfer torque, which is the rotational force generated by the engines that must be transmitted to drive various components of the helicopter, such as the main rotor system and other accessories.

Torque transfer is essential for the overall operation of the helicopter, as it affects the performance of the rotor system and, consequently, the aircraft's ability to lift and maneuver. The design and engineering of the pylon driveshaft ensure that it can handle the high torque loads that may occur during various flight conditions without failure.

In contrast, while power supply and fuel are important for the operation of the aircraft, they are transmitted through different systems and components. Electrical signals, although critical for engine management and control systems, are not a function of the pylon driveshaft. Therefore, the primary role of the pylon driveshaft is accurately captured by its function of transferring torque between the PRGB and TAGB.